sound/soc/codecs/ak5386.c

   1 /*
   2  * ALSA SoC driver for
   3  *    Asahi Kasei AK5386 Single-ended 24-Bit 192kHz delta-sigma ADC
   4  *
   5  * (c) 2013 Daniel Mack <zonque@gmail.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/of.h>
  15 #include <linux/of_gpio.h>
  16 #include <linux/of_device.h>
  17 #include <sound/soc.h>
  18 #include <sound/pcm.h>
  19 #include <sound/initval.h>
  20
  21 struct ak5386_priv {
  22         int reset_gpio;
  23 };
  24
  25 static struct snd_soc_codec_driver soc_codec_ak5386;
  26
  27 static int ak5386_set_dai_fmt(struct snd_soc_dai *codec_dai,
  28                               unsigned int format)
  29 {
  30         struct snd_soc_codec *codec = codec_dai->codec;
  31
  32         format &= SND_SOC_DAIFMT_FORMAT_MASK;
  33         if (format != SND_SOC_DAIFMT_LEFT_J &&
  34             format != SND_SOC_DAIFMT_I2S) {
  35                 dev_err(codec->dev, "Invalid DAI format\n");
  36                 return -EINVAL;
  37         }
  38
  39         return 0;
  40 }
  41
  42 static int ak5386_hw_params(struct snd_pcm_substream *substream,
  43                             struct snd_pcm_hw_params *params,
  44                             struct snd_soc_dai *dai)
  45 {
  46         struct snd_soc_codec *codec = dai->codec;
  47         struct ak5386_priv *priv = snd_soc_codec_get_drvdata(codec);
  48
  49         /*
  50          * From the datasheet:
  51          *
  52          * All external clocks (MCLK, SCLK and LRCK) must be present unless
  53          * PDN pin = “L”. If these clocks are not provided, the AK5386 may
  54          * draw excess current due to its use of internal dynamically
  55          * refreshed logic. If the external clocks are not present, place
  56          * the AK5386 in power-down mode (PDN pin = “L”).
  57          */
  58
  59         if (gpio_is_valid(priv->reset_gpio))
  60                 gpio_set_value(priv->reset_gpio, 1);
  61
  62         return 0;
  63 }
  64
  65 static int ak5386_hw_free(struct snd_pcm_substream *substream,
  66                           struct snd_soc_dai *dai)
  67 {
  68         struct snd_soc_codec *codec = dai->codec;
  69         struct ak5386_priv *priv = snd_soc_codec_get_drvdata(codec);
  70
  71         if (gpio_is_valid(priv->reset_gpio))
  72                 gpio_set_value(priv->reset_gpio, 0);
  73
  74         return 0;
  75 }
  76
  77 static const struct snd_soc_dai_ops ak5386_dai_ops = {
  78         .set_fmt        = ak5386_set_dai_fmt,
  79         .hw_params      = ak5386_hw_params,
  80         .hw_free        = ak5386_hw_free,
  81 };
  82
  83 static struct snd_soc_dai_driver ak5386_dai = {
  84         .name           = "ak5386-hifi",
  85         .capture        = {
  86                 .stream_name    = "Capture",
  87                 .channels_min   = 1,
  88                 .channels_max   = 2,
  89                 .rates          = SNDRV_PCM_RATE_8000_192000,
  90                 .formats        = SNDRV_PCM_FMTBIT_S8     |
  91                                   SNDRV_PCM_FMTBIT_S16_LE |
  92                                   SNDRV_PCM_FMTBIT_S24_LE |
  93                                   SNDRV_PCM_FMTBIT_S24_3LE,
  94         },
  95         .ops    = &ak5386_dai_ops,
  96 };
  97
  98 #ifdef CONFIG_OF
  99 static const struct of_device_id ak5386_dt_ids[] = {
 100         { .compatible = "asahi-kasei,ak5386", },
 101         { }
 102 };
 103 MODULE_DEVICE_TABLE(of, ak5386_dt_ids);
 104 #endif
 105
 106 static int ak5386_probe(struct platform_device *pdev)
 107 {
 108         struct device *dev = &pdev->dev;
 109         struct ak5386_priv *priv;
 110
 111         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 112         if (!priv)
 113                 return -ENOMEM;
 114
 115         priv->reset_gpio = -EINVAL;
 116         dev_set_drvdata(dev, priv);
 117
 118         if (of_match_device(of_match_ptr(ak5386_dt_ids), dev))
 119                 priv->reset_gpio = of_get_named_gpio(dev->of_node,
 120                                                       "reset-gpio", 0);
 121
 122         if (gpio_is_valid(priv->reset_gpio))
 123                 if (devm_gpio_request_one(dev, priv->reset_gpio,
 124                                           GPIOF_OUT_INIT_LOW,
 125                                           "AK5386 Reset"))
 126                         priv->reset_gpio = -EINVAL;
 127
 128         return snd_soc_register_codec(dev, &soc_codec_ak5386,
 129                                       &ak5386_dai, 1);
 130 }
 131
 132 static int ak5386_remove(struct platform_device *pdev)
 133 {
 134         snd_soc_unregister_codec(&pdev->dev);
 135         return 0;
 136 }
 137
 138 static struct platform_driver ak5386_driver = {
 139         .probe          = ak5386_probe,
 140         .remove         = ak5386_remove,
 141         .driver         = {
 142                 .name   = "ak5386",
 143                 .owner  = THIS_MODULE,
 144                 .of_match_table = of_match_ptr(ak5386_dt_ids),
 145         },
 146 };
 147
 148 module_platform_driver(ak5386_driver);
 149
 150 MODULE_DESCRIPTION("ASoC driver for AK5386 ADC");
 151 MODULE_AUTHOR("Daniel Mack <zonque@gmail.com>");
 152 MODULE_LICENSE("GPL");